Platyhelminth fauna of the Island of Sylt: a meta-analysis of distributional patterns and description of 19 new species

Abstract Over the past 70 years, numerous authors studied platyhelminth fauna near island of Sylt in eastern North Sea, each with a specific focus on varying aspects ecology, morphology or systematics, and most them dealing single habitat type. These data are combined new to get comprehensive view species richness, distribution individual across tidal levels sediment types resulting communities. So far, 398 have been recorded around island, plus still growing number unidentified undescribed species, particular from subtidal waters. The over (as defined by level) is described for known species. Neighbouring overlap composition, faunal composition changes continuously environmental gradients. per type mirrors sampling intensity varied between some 20 poorly habitats 150 well-studied intertidal sand flats. Corrected variations intensity, richness showed no significant differences only moderate variation levels. On larger spatial scale, three assemblages can be differentiated: supratidal harbours brackish-water (mesohaline upper polyhaline lower supratidal), polyhaline-marine wide tolerance physical factors marine (± stenohaline) With respect type, mud dwellers well separated supra- belt but less intertidal. Provided these rules general, I conclude given section coastline mainly depends ranges covered. Nineteen encountered during this study described.